1. Technical Field
The present invention relates to technologies for wirelessly transmitting data to a projector.
2. Related Art
As a network configuration of a wireless network, there are infrastructure mode in which devices perform communication with each other via a base station and ad-hoc mode in which the devices perform communication directly with each other. Each device identifies a wireless network by using a service set identifier (SSID) and connects to a wireless network having a common SSID. In infrastructure mode, an SSID is usually set in advance by an administrator of the network, and an IP address is usually set automatically by the base station. Each device can perform communication by using the IP address and the SSID. On the other hand, in ad-hoc mode, an administrator of the wireless network is not present. Therefore, in ad-hoc mode, one device (hereinafter referred to as a “master unit”) generates an independent basic service set (IBSS) network and an SSID for identifying an IBSS network, and sends a beacon signal including the SSID. Other devices (hereinafter referred to as “slave units”) can take part in a wireless network (an IBSS network) corresponding to the SSID by receiving the SSID and setting the SSID in a wireless adapter. Here, communication in which the other party is identified requires the IP address of the other party. In the past, the technologies for allowing a master unit to inform a slave unit of the IP address of the master unit by providing the SSID included in the beacon signal with the IP address have been known (see, for example, JP-A-2005-323117 and JP-A-2006-254301).
Incidentally, when the technologies which provide the SSID included in the beacon signal with an IP address are used, if the IP address of the master unit is changed, the master unit generates the SSID again and transmits the SSID. Here, since it takes time to perform scanning via a wireless network, a slave unit sometimes accumulates the acquired SSID information for a predetermined period. In such a case, the slave unit has a plurality of SSIDs, that is, an SSID acquired before address change and an SSID acquired after address change. In this case, even though the wireless networks are generated by the same master unit, the slave unit cannot determine which of the wireless networks corresponding to the SSIDs is a wireless network to which the slave unit makes connection.